If I was chosen to wear an invisible cloth, the good deed I would do is something simple. Simple things might not have the biggest impact in life but it would certaintly make someones day. These deeds include taking out the trash for my neighbors and opening the door for an incoming stranger entering a store and even helping the elderly cross the street if I see they are in need of the assistance. I know these simple tasks can change someones mood to the better.
It really isn't something special like saving a young boy from a burning building or stopping a robbery but it will do. Good deeds do not have to impact everyone in some way but impact a certain individual. Sometimes, the people that seem are not in need of help are the ones who are suffering the most. I know I can make a huge impact in that old lady or that woman with the four kids ready to enter the grocery store. The simple things urn out to have the biggest impact.